Abstract: The chelating fluid for enhanced oil recovery in carbonate reservoirs and the method of using the same utilizes a chelating fluid injected into a carbonate oil reservoir through a fluid injection system. The chelating fluid is a solution of a polyamino carboxylic acid chelating agent in brine, with the polyamino carboxylic acid chelating agent having a concentration of approximately 5.0 wt % of the solution, with the solution having a pH of approximately 11.0. The polyamino carboxylic acid chelating agent is preferably ethylenediaminetetraacetic acid (EDTA). The brine preferably has a relatively high salinity, with a sodium chloride concentration preferably on the order of approximately 18,300 ppm.

Abstract: The enhanced oil recovery using seawater and EDTA (ethylenediaminetetraacetic acid) is a method that uses injection of EDTA in seawater to enhance the recovery of oil from sandstone reservoirs. The EDTA may be introduced into seawater during the initial extraction of oil from the reservoir by seawater injection, or a solution of EDTA in seawater may be used to flush residual oil from the reservoir after the initial extraction by seawater injection. In either case, the EDTA is present in about 1.0 wt % to about 5.0 wt % of the seawater solution, and the solution has a pH of between 10.5 and 11.0.

Abstract: The chelating fluid for enhanced oil recovery in carbonate reservoirs and the method of using the same utilizes a chelating fluid injected into a carbonate oil reservoir through a fluid injection system. The chelating fluid is a solution of a polyamino carboxylic acid chelating agent in brine, with the polyamino carboxylic acid chelating agent having a concentration of approximately 5.0 wt % of the solution, with the solution having a pH of approximately 11.0. The polyamino carboxylic acid chelating agent is preferably ethylenediaminetetraacetic acid (EDTA). The brine preferably has a relatively high salinity, with a sodium chloride concentration preferably on the order of approximately 18,300 ppm.